It has long been recognized that the ocean has great potential for developing energy using environmentally friendly methods. Since the 1800's the art has examples of ocean waves being used to harness power. Generally, attempts to harness power from the ocean can be divided into two categories. Attempts have been made to use the forward motion of either waves or underwater currents to push paddles or the like that drive turbines. U.S. Pat. Nos. 675,039 and 1,887,316 are among the earliest types of these. The second main category is to use the up and down motion of the ocean waves or swells. These methods, while using ocean power initially to drive the system, are most favorable designed when they are less damaging to marine life. This is where the most recent work is being done.
There have been many attempts to use the up and down motion of ocean water to harness power and these can generally be divided into three main categories. The Tapered Channel or Oscillating Water Columns (OSC) methods generally use waves to push air through chambers to drive turbines, U.S. Pat. Nos. 4,441,316 and 6,360,534 are examples of these. Some of these recent methods use the forces generated by the sea very efficiently. In U.S. Pat. No. 5,191,225 the air movement created in both the forward motion of the wave and receding motion of the wave is harnessed using a Wells turbine (U.S. Pat. No. 4,221,538). Overtopping methods use water that drop from a higher elevation to drive turbines, the Wave Dragon (www.wavedragon.net) is an example of this type of method. Power buoys use elevation changes inside a buoy to generate power, U.S. Pat. Nos. 4,434,375 and 6,765,307 are examples of these.
While most of these are in experimental stages at this point, one can see problems with many of these methods. Tapered Channel or Oscillating Water Columns usually are deployed at the shoreline, prime real estate in many parts of the world. Overtopping systems can be deployed at sea but most of their working components come in direct contact with corrosive ocean water. While some of the buoy systems house their working components inside a closed buoy, the advantage these systems gain is in direct relation to the relatively small distance traveled during the up and down movement of the buoy on the wave.
Since wave heights and ocean swells very widely throughout the world but most generally average two to four meters (a relatively small amount) some attempts have been made to increase this relatively small movement by using some sort of mechanical advantage, U.S. Pat. Nos. 6,574,957 and 6,626,636 are examples of these. While wave heights can be mostly counted on to be fairly consistent at one location, at certain times, intervals of smaller waves can be encountered and any mechanical advantage should be able to be changed to reflect these conditions. During storms and such, methods to disconnect from these extreme circumstances have to also be explored.
While some of these prior devices have some parts of their systems that work somewhat well to harness the oceans energy to produce power, all these prior devices have reasons to be commercially unacceptable. It would therefore be a significant advance of the art to provide a device that uses the environmental friendly method of using ocean waves to harness electric power while at the same time being benign to marine life. It would also be a significant advance of the art to be able to deploy this method off shore on either sea bed attached or floating platforms and use non-corrosive air to drive turbines in both directions using Wells type turbines. It would be a further advance in the art if the relatively small forces contained in the up and down movements of waves could be multiplied using some sort of mechanical advance to produce more power per unit (cycle) while at the same time providing for an adjustment at times of calm seas as well as a disconnect from the powerful forces of the ocean when conditions warrant.